A.目的站不可达B.改变路由C.时间戳请求D.数据报时间超过以下属于ICMP差错报文的选项是（）。……

多项选择题以下几种分类方式属于正确的VLAN报文类型的有（）。

A.基于端口
B.基于MAC地址
C.基于网络层
D.基于IP组播

多项选择题以下哪一款AN5006-07B2H机型的软件版本加入了解决烽火ONU私网管理IP与局方MGC地址冲突的解决方案（）。

A.R3.07.09.02
B.R3.07.09.03
C.R3.07.09.04
D.RP0102

多项选择题When designing OSPF networks，it is not recommended to have an excessive number of routers in any single area.Which two of the following statements describe the consequences of having too many routers in an area（）。

A.Excessive LSA traffic.
B.Frequent routing table recalculation.
C.Frequent adjacencies table recalculation.
D.Unacceptable number of reachability errors.

多项选择题OSPF协议定义了5种网络类型，哪些类型的网络需要选举网络Designated Router（DR）、BackupDesignated Router（BDR）（）？

A.Point-to-point
B.Nonbroadcast multi-access
C.Point-to-multipoint
D.Broadcast multi-access

多项选择题You are the administrator of the large OSPF network and are considering dividing it to multiple areas.What are two advantages of configuring multiple OSPF areas（）？

A.It eliminates the need for a DR or BDR in the OSPF network.
B.It eliminates security concerns by segregating portions of the network.
C.Type 1 and 2 LSAs are confined to a single area，reducing routing overhead.
D.Area members have smaller topological databases than if the network was one large area，requiring less CPU to derive routes。